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# SPDX-License-Identifier: (GPL-2.0+ OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/clock/nvidia,tegra124-car.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: NVIDIA Tegra Clock and Reset Controller
maintainers:
- Jon Hunter <jonathanh@nvidia.com>
- Thierry Reding <thierry.reding@gmail.com>
description: |
The Clock and Reset (CAR) is the HW module responsible for muxing and gating
Tegra's clocks, and setting their rates. It comprises CLKGEN and RSTGEN units.
CLKGEN provides the registers to program the PLLs. It controls most of
the clock source programming and most of the clock dividers.
CLKGEN input signals include the external clock for the reference frequency
(12 MHz, 26 MHz) and the external clock for the Real Time Clock (32.768 KHz).
Outputs from CLKGEN are inputs clock of the h/w blocks in the Tegra system.
RSTGEN provides the registers needed to control resetting of each block in
the Tegra system.
properties:
compatible:
const: nvidia,tegra124-car
reg:
maxItems: 1
'#clock-cells':
const: 1
"#reset-cells":
const: 1
nvidia,external-memory-controller:
$ref: /schemas/types.yaml#/definitions/phandle
description:
phandle of the external memory controller node
patternProperties:
"^emc-timings-[0-9]+$":
type: object
properties:
nvidia,ram-code:
$ref: /schemas/types.yaml#/definitions/uint32
description:
value of the RAM_CODE field in the PMC_STRAPPING_OPT_A register that
this timing set is used for
patternProperties:
"^timing-[0-9]+$":
type: object
properties:
clock-frequency:
description:
external memory clock rate in Hz
minimum: 1000000
maximum: 1000000000
nvidia,parent-clock-frequency:
$ref: /schemas/types.yaml#/definitions/uint32
description:
rate of parent clock in Hz
minimum: 1000000
maximum: 1000000000
clocks:
items:
- description: parent clock of EMC
clock-names:
items:
- const: emc-parent
required:
- clock-frequency
- nvidia,parent-clock-frequency
- clocks
- clock-names
additionalProperties: false
additionalProperties: false
required:
- compatible
- reg
- '#clock-cells'
- "#reset-cells"
additionalProperties: false
examples:
- |
#include <dt-bindings/clock/tegra124-car.h>
car: clock-controller@60006000 {
compatible = "nvidia,tegra124-car";
reg = <0x60006000 0x1000>;
#clock-cells = <1>;
#reset-cells = <1>;
};
usb-controller@c5004000 {
compatible = "nvidia,tegra20-ehci";
reg = <0xc5004000 0x4000>;
clocks = <&car TEGRA124_CLK_USB2>;
resets = <&car TEGRA124_CLK_USB2>;
};